Well, don't necessarily buy a used Phantom from eBay not because you shouldn't trust them but because used Phantoms on eBay bring almost list price. You won't save much money and might as well buy new. As for your paranoia of online trading, eBay is excellent and has extensive legal backing as well as Paypal-sponsored refunds and a myriad of other protections. I have yet to have a bad transaction on eBay and as long as you're mildly intelligent and don't buy anything that's "haunted", "holy" or has any non-physical properties, you won't have a hard time either.
That said, there are stock-class markers in the sub-$100 category. Most immediately coming to mind are the Sheridan PGP and the Sidekick pistols. Not only are both wonderful markers, you can carry them as backup while playing semi if you get a holster. Even the original Nelspots are stock-class if you're looking for a collector's item as well. Don't expect them to shoot like a Phantom, however...
Choices in the sub-$200 category include barebones Phantoms, converted sterlings or snipers, possibly other custom conversions (any pump with a stock tube and 12-gr. changer attached so long as the stock tube meets specs) and some of the nicer sheridans like the P-68 SC (basically the PGP with a longer barrel, pump and feed tube).
The real question is this: How serious are you about playing stock class and what kind of care do you take of your makrers? If you just want a beater gun to take out once a day, shoot a few rounds through it and then go back to your semi, look at the PGP and Sidekick. Why? They're both darn near indestructible and super-reliable and even though they're not the best shooters out there, they can easily hold their own for the occasional game or two. Most importantly, they're cheap. PGP's can be had for less than $75 if you're lucky (get the old style - the newer ones break paint) and the SideKick stock retails for under $65. Check that out HERE
. Personally, if you want a high-quality stock class marker for under $100, give a serious look at the sidekick stock.
If you're really serious about stock play, then save up and get yourself a Phantom - you'll never look back. And yes, they're really that good. I played 3 v 3 speedball just yesterday and swept the field numerous times. Eliminated the entire other team of tournament super-semi shooters with just 8 rounds in one particular game. I just couldn't miss. (well, technically I did 5 times, but whatever) Then again, not all games are equal and sometimes you lose. It happens. Trust I'm I'm sporting plenty of bruises, too, so keep in mind even the best markers aren't going to make you invincible.
The important thing is to have fun when you play and if you want to enjoy yourself using a stock-class marker, you have my encouragement. You won't go wrong with any markers I've mentioned here, but keep in mind that I may be forgetting a few. Good luck and let us know how it turns out!