Once you move outside low Earth orbit (i.e. outside the magnetosphere) you also have to deal with much more radiation so using regular commercially available hardware for the DC is no longer an option so you're looking at another 10-100x increase in cost for the chips alone (and at worse performance because radiation-hardened chips are literally generations behind at this point). You'll also need signficantly more (very heavy) shielding and that also adds to your launch costs. Of course OceanGate is a good reminder that billionaires don't always concern themselves with such trivialities as using equipment and materials actually suited for the task if it means they get an opportunity to brag about how they're disrupting the market by jerry-rigging mission critical components.
Speaking in terms of feasibility again, availability isn't the only problem you'd be facing. Obviously latency is going to be horrendous because of the incredible distances involved but really there's just literally no infrastructure you can piggyback off of. You could potentially achieve data rates of up to tens of Gbit/s even from L4/L5 (stable orbits 1 AU away) using something like NASA's DCOS but this requires optical ground stations or LEO relays, bringing the weakest link much more within reach again.
Even if you somehow manage to develop sufficiently ruggedized variants of reasonably modern chips, add the necessary shielding and develop and build out the necessary communication infrastructure from scratch (remember that we haven't even considered how we generate enough power to run the actual DC itself) and are also willing to accept the disgusting latency and packet loss ratio, the elephant in the room remains that DCs on the ground require constant maintenance to operate and replace failing parts. DCs in space can only ever be disposable - once any redundancies run out, they're just very expensive space junk.
But you have a point: putting it in space is inherently ridiculously expensive. Getting it to L4/L5 is only insignificantly more expensive than getting it to L1/L2 but assuming you can fit the entire DC in a single Falcon Heavy (so you don't also have to worry about assembling the entire thing in space across multiple launches) you're limited to a payload of 25 t and the launch itself already costs you $120 million. Of those 25 t only 7 t or so can be spent on actual compute so your space DC would probably be constrained to the equivalent of about 500 GPUs (assuming this is for AI because everything is for AI these days). Most of the weight budget and the actual cost however would be eaten by all the structural and infrastructural parts required - in terms of cost for compute a space DC that fits in a single Falcon Heavy is easily an order of magnitude more expensive than one built in the US today and those don't need to be replaced from scratch when a significant chunk of the initial parts have degraded.
TL;DR: Building a DC in space is easily 10x as expensive, requires technology that hasn't been developed yet, requires you to also build all infrastructure needed to actually operate and connect to it, and in the end just gives you a high latency low performance Beowulf cluster that is rapidly converting itself into an expensive piece of space junk if random debris doesn't kill it first.