big bucks on dvd player worth it??

Do not move up now.
Agree that the HD situation is moving, and the 1080p is coming.
I would wait for awhile.
The player you have is good enough.
(Unless you just bought a $10,000 HD panel.
If you can afford a $10 grand TV, get a new player.
If not... wait.
(I bought a new $4K plasma, so I bought a Denon with HDMI output. Otherwise my old DVD player would have been good enough.)

The newer top rated cheap players are no where near as good as your 59avi for video.
The Pany s-97 that I just sold here is a full 30% inferior in overall picture quality than my Onkyo SP 1000 on my 110 screen with Optoma H-78DC3 PJ.
Your 59avi is close to being as good as an SP1000...so why bother if its only for picture quality.
If it were for audio, build,ergonomics and video....it would be worth upgrading.
I would also wait for hi res dvd to finally show up.

I got so tired of waiting for hi res dvd that I bought an hdmi JVC 5u DVHS player which is superior to any dvd player for picture quality ...and suprisingly enough... has better audio on most tapes... DD and DTS.

If these tapes are any indication....hi res dvd should be worth the wait.
The only reason I plan on keeping my Onkyo SP 1000 after hi res gets here is because I preferred it for redbook and sa-cd over the Sony xa777es and Marantz sa-14.....otherwise I would sell it before hi res gets here.

Most of your highend dvd players are geared for better audio not video. I have a Theta Carmen II and the video is very good but probably not as good as or any better than the unit you have, although as a transport the audio is excellent. The Ayre DX1 and Krell DVD standard have excellent video qualities but boy are they expensive. The Pioneer 5910 probably has as good a video as any thing available. I am not interested in the upcoming new formats as there will be very little software to go with the expensive players, I'll wait until the war is over. Why buy something when you may have 20 titles to play.