I think,...
the A8 is a better deal in the $175 range, unless it's really-really mint. I bought a mint R8 for $250 a few years ago, if it's anything to'ya. I'm just using this as an example. Ebay deals vary by the day, and YMMV.
The A8's reels are belt driven and the 388's reels are servo motor driven. That's a significant difference in build quality, not to mention the A8's plastic with a metal sub-frame, and the 388's all-metal construction with wood side panels. -Huge difference-.
Although the A8 runs 15ips and DolbyC, the 388's an almost unbeatable package, running 7.5ips & dbx, w/integrated 8x8x2 mixer. IMO, the 388 with 7.5ips & dbx somehow sounds better than the A8 with 15ips & DolbyC. Honestly, I've never been impressed with DolbyC, but I've always been happy with dbx. Again, YMMY.
Plus, consider that the A8 (std) only records 4-tracks simultaneously/max, and the 388 records 8-simul/max. The upgraded A8LR is the one that records 8-simul/max, but it's more rare to find, and costs a bit more than the A8 (std).
The 388, in total, is really hard package to beat. If you get the A8, which is an acceptable baseline, you should consider that the "matched" mixer to the A8 is the Fostex 350, which is really cheezy, and nowhere on par with the 388's mixer section.
The 388 will do SMPTE sync, with DIY cabling and a compatible synchronizer, and the A8 does not. You'd have to step up to
the Fostex Model 80 or R8 to get plug-compatible sync option.
Just some things to consider.