92 Gt W/351w Advice Needed

On the shipping, are you going online and getting estimates from UPS, USPS, and Fedex before doing your pricing? Doing it that way avoids surprises, and if you do the shipping online, its cheaper. Also, USPS has priority flat-rate boxes. Walk into the post office, grab the boxes for free (I keep about five of them in different sizes in my truck, I sell a ton of parts on Ebay) put the part in the box that fits before you list it, and you already know the shipping price.

I use Priority Flat Rate small boxes and envelopes for most small stuff that is too heavy to ship first class, FedEx Smartpost for most heavier stuff, and UPS Ground on the rare occaisions that its cheaper than either of them.

Also, if you don't have a scale, get one. A bathroom scale will work as long as it goes to one decimal point, you can do simple math from there to figure out ounces. If the item itself isn't heavy enough, just weigh yourself, then weigh yourself holding the item, subtract the difference and you have your item weight. (AWS makes a pretty awesome shipping scale that has 110lb capacity for less than $30 on Amazon, it paid for itself in more accurate shipping prices in two weeks for me.) Also, ALWAYS package yourself, as the shippers all charge astronomical prices for boxes and packing materials. I get everything but my bubble wrap and shipping labels for free. I get boxes from work, from parts stores, and re-use boxes from Summit, Amazon, and other Ebay users, as well as re-use any packing material I can and old newspaper. I buy my bubble wrap in bulk rolls. Another reason to package them yourself is because all three shippers charge by "dimensional weight" which is a combination of the item's actual weight and how much room it's going to take up on their trucks/planes. I frequently cut down boxes to smaller sizes, as a box that's 18x18x18 costs more than twice as much to ship as a box that's 18x18x9, and if that's all the room I need, I'm going to save the money!