Cost for replacement of baseboard radiator?

[Peter Morrissey]

Looking at a rehab duplex to buy and hold. It has boilers which is a new thing for me as they are not real common in our area. The boilers look reasonably new. My concern is with the baseboard radiators. The fins look pretty beat up and rusted in some cases. It would help to get a ball park on replacement of them as unlike most things I look at, I have no idea what to estimate. Most of them are roughly 6-8 feet long.