On Myarc RS-232 cards, there is absolutely nothing special about them that increases the price over the TI card. As a matter of fact, it actually sells for less than they do because the RI card can be modified to add HDX capability. Myarc disk controllers sell for between $150 and $200 on average, sometimes a bit less, sometimes a bit more--and the 80-track mod really does nothing for the selling price, as those ROMs are easy for anyone to install (and they can be purchased for under $10). p-GRAM boards usually sell for $125 to $150, sometimes more. As already noted though--if you want to know the current price, put them on eBay with a reasonably low starting price, and they will settle in at what people are willing to pay for them. That's really the only way to determine their current value.