I would say if the block is good, just the chains/guides are bad, maybe $2-2.5k if the rest is well sorted and tires are solid.
If the block is toast, it is new engine time and then $1-1.5k.
To be honest, if it is just the chains, for about $1k in parts one can get everything that needs to be replaced - replaced. It is all there, and taking off the intake makes even the valley pan an added 15 minutes. It can be done in a weekend.
If I were looking, I would look at the overall condition, the tires and the block. The rest doesn't really worry me.
I would either pull the engine and do the torque converter and RMS, plus all the other items (maybe even the valve stem guides - leaving head on) or leave the engine in and do the timing guides, engine oil pan, hoses, intake/pcv, valley pan, pulleys and belts, water pump/thermostat, valve cover gaskets, vanos, and all related seals. Everything is coming off - may as well do it.
The thing that scares me on yours is whether the guides are the only issue, or did the block get toasted. It has been about 50/50 on the posts I have been reading. If the guides were left broken for too long that is not good.