Is your BCM actually dead (no lights or fans on power up) or it will it just not boot up? If it won't boot, then it's your hard drive which makes it perfect for an emetro replacement. The hard drive is removed anyway and replaced with an SSD to turn it into a digital gateway.
As for pricing, you should go to the emetrotel website and use their find a reseller link, or just give them a call. They'll help you along. Around where we are, we use a budgetary number of $200.00/per set as a guideline. Could be more or less depending on if you want other available options or set replacements etc. I find the ROI on these things to be anywhere from 6-18 months and if you move to SIP trunks, it's even less.