I thought I was would share my creative solution to fixing some odd shipping issues. First I'll explain the situation.

I apologize in advance for the MESS of words below, but I'm explaining it as well as I can...

I have a client who sell aquatic plants, snails, shrimp, and driftwood.
The shipping issues were these -
1- for plants, they come in all different sizes. Small plants fit ina box that can ship for $12, Medium ones fit in boxes that ship for $16, and the big plants have to go in a box that ships for $22, but that is based on physical SIZE, not weight, price, or anything else.
2- Snails are small and light weight. They want people to be able to buy an unlimted number of them and them all ship for $8.50 whether you buy 1 or 100.
3- Shrimp are sold in batches of 25. They can put up to 2 batches (50 shrimp) in one box that ships for $8.50, so for every 2 batches, there must be an extra $8.50.
4- If you buy snails and shrimp together, you should not have to pay shipping for the snails, because they can go in with the shrimp.

So - here was my solution, and I hope it helps someone else with coming up with creative solutions.

Keep in mind custom programming was not an option on this job.

Where we started -
•Problem: Shrimp were going to be tricky because there had to be an $8.50 surcharge for each set of 2 units. So if there were 3 units, you would be charged 3 x the unit price, plus $8.50x2 for shipping.
•Solution: Though it's cheating, we set the BASE price of the shrimp colonies at $15.95 so it would display the proper price on the product page, and also set to "product always ships free". We then set up an attribute for "pick a number of colonies" People rarely order more than 2 colonies, so we made this a drop down and the first was "one colony - Shipping inlcuded" with added $8.50 for shipping. The second option in the dropdown was "two colonies - Shipping included" which added $24.45 (for the shipping, and the extra colony) There is a note on the product page, just about the add to cart explaining why you see a higher price when it adds to the card. Not 100% best way I'm sure, but it works...

•Problem: How to determin basic shipping, when weight won't work.
•Solution: Since the client is familiar with what plants need what size boxed, I had them use the weight field to put in a "size". The way we worked it was this - Very small plants were assigned a weight of .1lb. Medium sized plants were assigned 10lbs. Large plants were assigned a size of 100lbs, and Extra large plants 1300lbs. We then changed the name of the "Table shipping" module to "Standard Shipping" and set it to look at weigh. For orders totaling up to 9.99lbs, we know it's all small plants that will fit in the small box, so the table was set to $10 for those "weight" orders.
For orders totally up to 99.99lbs, they know they need a medium box that the shipping cost is 14.50. Orders totalling 100-1299.99lbs are large plants (up to 10 of them in which case they need a bigger box anyway) so shipping for that range is $18, and finally orders over 1300lbs total, are either lots of large plants, or 1+ xtra large plants, needing the extra large box, so 1300+ have a table rate of $22.50.
You do have to go into your configuration>shipping/packaging menu and set the maximum package weight to something like 22000lbs.

•Problem: Snails should have a single flat rate shipping price of $8.50, no matter how many are bought.
*Solution: Changed the name of the Free Shipping Options module to "SNAILS ONLY SHIPPING". We told it to look at the weight and anything less than or equal to zero ships free, but then in the "free" box, we set the price of $8.50. This did require changing the Includes>langages>English>modules>shipping>freeoptions.php

•Problem: If you are buying shrimp AND snails at the same time, the snails can be packed into the boxes with the shrimp. The shrimp already have shipping included in their pricing, so you should not have to pay any extra. But the Shrimp are set as "ALWAYS SHIP FREE" since the price is built in, and snails have a weight of zero making them have a "free shipping" price of $8.50.
Solution: Change the "In Store Pickup" option to read "SNAIL & SHRIMP PACKAGES & Local Pickup" The the description is to use this free option if you are ordering snails and shrimp at the same time. It's kinda of an honor system, but it works. So in that case when they get to the shipping page, they see TABLE RATE for $10.95 (because the shrimp are set to a weight of .1, so they don't get an $8.50 shipping fee) "SNAIL ONLY SHIPPING" (free shipping options) for $8.50, or SNAIL & SHRIMP PACKAGES/LOCAL PICKUP - FREE