I'd go for an interarms Mark X as the least expensive starter mauser. Solid, accurate, require zero modification, and can be found for $300-$400 ready to go.
Especially since the word has gotten out about the "sleeper" FNs, I think interarms are the best value on the market
They can be a bit rough, but with some work with abrasives, they can be slicked up pretty smooth. Of course, keep the abrasive off the lugs...
Cheaper than tackling a military action. Those are nice, but be ready to spend a good bit of money, more than the the cost of a Mark X.
And sleeper J.C. Higgins FN's are still out there... Those FN's are gonna be slicker than a Mark X.
DF