Not to discount that that shop is one of the best around, but bragging rights of how much money you might spend on a motor rebuild can be similar to bragging rights to how much power it produces, with all due respect. The other key question is just what YOU really want to have when it's all said and done? Remember, too, that a "rebuilt motor" MIGHT add a little bit of additional value to the car when it is sold, but a $10K motor is no better than a $3K motor, in that respect.
Now . . . DO go for the tour and use it as an educational experience. Check out the other shops, too. THEN you can get a better idea of what involved and what is gotten "for the money".
On the other hand, $10K might buy you a newer car that might need some work, if that might matter. You can probably get a crate engine or reman short/long block that can do just as good of a job for less money, too.
As far as machine work goes, it's more about labor time than the size of the motor. Where engine size becomes operative is when you start to buy parts and such. Which is why some mass rebuilders can offer similar items for less money, just be careful of WHICH one it is, by observation, and which market they might be targeting. Kind of like Jasper and other similar rebuilders tend to target the better private repair shops and such. When I looked at Jasper (about 15 years ago), their prices seemed a bit high, by comparison, but they also send every little thing needed to complete the job (i.e., belts, hoses, clamps) correctly. Several different things to consider.
On the parts side of things, DO investigate the brands and such each rebuilder might use. As in no need for forged pistons in a street car, for example. Look for OEM-level quality in all areas, as a benchmark of sorts compared to what the shop might use. Might be good to upgrade to better gaskets and such, for a little more cost. Do spec that you want a roller timing chain set, too.
DO be a good comparison shopper so that you get the best value for what you desire to end up with.
Enjoy!
CBODY67