Various info I have about shermans give an average cost of 50.000 $ ( around 1940). And dont think a hellcat for exemple could be less expensive.
I have that as exemple everyone can access. http://web.inter.nl.net/users/spoelstra/g104/cost.htm
However basic cost even interresting is not all. A rich country can afford to pay more. Others important factors are.
Did the country have access to strategic raws ?
How many men/hours to produce a tank. On that, how many men/hours providing by an highly skilled workers are needed.
And once your tank is produced, have you fuel for it ? Have you oil to train crews ? Have you even planed and can you affort a long training planing ?
Have you logistic to support your tanks ?
Just for exemple ; the tiger around 55 tons, but no maintenance tractors for towing it on battlefield if disabled.
It stay an interesting and informative post anyway.