Agreed! And we’d love to. Unfortunately our development resources are limited, and there are lots of other products people are interested in too.
For some context around the relevant challenges and expectations - sustainable production of a more affordable vehicle requires development work across a range of products (so comes about via incremental releases rather than one big one), while also typically requiring substantial production quantities (to benefit from economies of scale), so even once the underlying technology is established there’s likely to be a ramp-up period for production.
An entire vehicle release is a significant undertaking, and a cheaper variant of an existing vehicle is unlikely to be released as a surprise - there’ll be several steps along the way 
Thruster design aside, I’d personally be interested in a vehicle with something like a Raspberry Pi Zero 2W as the control computer, a stripped back Navigator variant with fewer expansion ports, just a few thrusters (maybe vectorised with servos, or control surfaces for steering and a single thruster for propulsion, or other low cost advanced control mechanisms), possibly one or two fixed cameras, and less surrounding hardware required to contain everything.
Hopefully I’ll be able to make time for something like that once I get back to my StaROV project, but there’s still some pretty major documentation work I’m focused on in the meantime, so I don’t expect that’ll be particularly soon 