Is THETA DSPro still an advisable purchase ?? Tks

I got an offer for about 400 USD 2nd hand.
Does it still keeps up with the new converters or better leave it off.??
I own one and still like it. Go for the mk. IIIa version, the last iteration made. Transport quality will still make a big difference (I use one of Theta's own). Employ the balanced XLR data connection if you can. $400 is a good price for these IMO (clean condition IIIa version - others can be less). The front panel source selection switch and lock indicator LED are commonly touchy (can seem to have a mind of their own) in this model. Try this Theta if you like the sound clean, extended, and impactful, with a big soundstage and solid 3-D images, but not if you prefer some obscuring warming-over of poor CD's. The DSPro Basic IIIa will not sweeten the top end or romanticize the mids, and the overall balance is a little cool and dry, but never flat, dull, or overly mechanical. (Ultimate transient precision, image focus, and treble clarity can be improved with a good jitter-box like the Monarchy DIP, and even more with a balanced-AC PLC and a decent PC, I have found.)
Unfortunately the version offered is the DSPro Prime !
Still valid when compare to more modern architectures ??

As a transport I plan to upgrade to a CEC when possible and definetely whatever transport will be I will use the AES/EBU being one of my criteria in selecting transports
$400 is way too much for a Pro Prime. You can get a Pro Prime IIa for that price and the IIa is vastly superior. I've owned them both.
Elgordo, please consider that I live in Europe where USA products prices are normally much higher.

The 2nd hand market is the same.

To give an idea most of USA retail prices are 50-60% higher in Europe.
The Prime was below the Basic in the Theta lineup, which from bottom to top went Cobalt, Prime, Basic, and Gen V. From what I understand, the Pro Basic IIIa is a big step up from the Prime IIa, and essentially pretty similar to the balanced version of the Gen Va with the exception of the latter's discrete output topology (having IC op-amps instead, but actually utilizing a more costly Burr-Brown chipset in the DAC, for some reason, than does the higher-priced model!), but in a smaller chassis without the internally shielded subcompartmentalized construction. FWIW, most Primes on A'gon seem to go from about $250-$500, and Basics from about $500-$800, depending on iteration and condition. (BTW, in the case of the Basic IIIa, I consider that to be a great bargain for a top-manufacturer product that sold new for about $2,700 just a couple of years ago.) Maybe it would be economical to buy a Basic IIIa used from the US, pay the international shipping, and convert the line voltage setting if possible. You could try contacting Ed at Theta for info about the last item, he's a great guy to deal with concerning their discontinued models.
Zaikesman , tks for the comments.
How does a Chroma 396 position in the list ?

I know it is une of the latest stereo models and possibly more good sounding ??
It should not have Theta proprietary DSP, but it a good choice ??
I forgot about that - I think the Chroma was the replacement for the Cobalt (still with the half-width chassis?), but most likely remained below the Prime and certainly the Basic. It might be a fine choice if you can get one cheaply enough, although not expected to sound as good as a Basic or probably even a Prime (in their later versions anyway). Try whatever fits your budget, and is priced right to resell without a loss if you don't end up liking it. Or maybe focus on things you can audition locally first - you might find a DAC other than a Theta that fulfills your wishes, or even an all-in-one CDP rather than a separate converter. Good luck!