Better to buy a 1.5, or a new one and downgrade?

First off, I apologize if this is a stupid question.

I've been thinking of picking up a PSP since it came out that you can play PSX games on them. eBay is crawling with 1.5s, so I figure it'd be easiest to just buy one of those. Is that the best way to go, or should I buy a new one and downgrade?

I am interesting in buying new games to play, and I realize that will require upgrading the firmware. But if I get a 1.5, I can just buy the game, find an ISO, and run it off the memory card, right?

Am I missing out on anything by not using custom firmware?

Thanks for all the advice, everybody.

I've been thinking of picking up a PSP since it came out that you can play PSX games on them. eBay is crawling with 1.5s, so I figure it'd be easiest to just buy one of those. Is that the best way to go, or should I buy a new one and downgrade?

Well, i wouldnt suggest purchasing a 1.5 off ebay as the motherboards tend to be manufactured cheaply because theyve been made by an outside party rather than sony. I would suggest trying to find something with firmware of 2.80 or lower so that you can downgrade without purchasing a game and your pretty much gauranteed that sony made the motherboards.

I am interesting in buying new games to play, and I realize that will require upgrading the firmware. But if I get a 1.5, I can just buy the game, find an ISO, and run it off the memory card, right?

Yes that is correct.

Am I missing out on anything by not using custom firmware?

Well custom firmware combines 1.50 as well as whichever firmware you choose to upgrade together so you get the best of both worlds. No one uses 1.50 anymore since its included in custom firmware.

Thanks for the input, Staxx. I appreciate it.