cheap used transport vs cheaper cdp w/ digital out

my venerable Rotel 855 is on its last legs and need to decide if a VERY cheap used transport ($350-$450)offers ANY sonic improvements over an even cheaper ($150-250) yet decent used transport with coax or optical outs. I've always wondered what you guys think about this. I think any discussion the community might offer would be of real value for us financially challenged audiophiles. thanks as always.
Find an old Theta Digital transport on eBay. Ones that sold for $1500 to $8000 new, now sell for $300 to $1000. Built like tanks. There are newer DVD/CD transports as well, but they will still cost a lot used.

There are quite a few for sale here on AgoN as well, but eBay usually has better bargins, so check around. The older models to look for include, Basic I & II, Data Basic I & II, Pearl, and Jade. They all will be a giant improvement over your old Rotel.

Some are based on Laserdisc players, others more traditional CD transports.

If not for you or too expensive, any used decent former higher end Pioneer, Toshiba, or Denon DVD player will work OK, for not much $$.
Look for a used broadcast cdp; I found Denon DN c-680 on eBay for $88--it sells new for $1,000, it's built like a tank, and has coax and xlr digital outs.
The Thetas will indeed be a huge improvement over your Rotel while they work, but I have on three different occasions (Data Basic One, Data Basic Two, Voyager) convinced myself that the exterior construction (which is indeed tank-like) and a great price had to mean a good used deal, only to end up with indifferent reliability. My learning curve isn't steep, but it does slope upwards: the fourth used transport I bought was a Wadia, not a Theta. The tank stays pretty much the same, but the maladies don't linger on.
wow dar, that is good information, interesting as well,my budget is more towards a cal transport, but same as you i always just wanted a tank w/out malady, i just want to play music(and not waste money on a cdp when i only use the digital outs). looks can be deceiving, what looks like a tank might be just a marketing illusion. God/the devil is in the details as they say. unless a cheap transport really does offers long term reliability, as nice as they are that would make it financially imprudent. really thanks for the insight.