Sigma were the official Martin budget line.

Here in the UK you can probably get a used Sigma DM2 for about £120, DM4 about £200 - both streets better than any new guitar at the price, with quite a fair impersonation of the ringing Martin sound.

I refurbished a DM4 for my daughter with a shadow pickup and a fishman preamp and it is nice. I have told her if she ever decides to sell it I will give her £500 for it.

A very basic L'Arrivee will cost you about £500. A top of the range one, about £2,000. I don't call that "low priced"