Solid name has other extensions taken and a couple developed. Since they have been developed then you have a lot of chances to get an end user. .COM, .BIZ and .CA looks as your natural first clients to look for a sale. Email them but be realistic with the price, remember they do not have any reason to buy it other than having a second extension, they do not need it at all so do not act like you have the ultimate option for them. Leave them to make an offer first, being realistic you can aspire up to mid xxx.