I don't know your financial situation, but my knee-jerk reaction would be that, as much as a make it a point to pay off my credit cards every month to avoid interest payments, I'd pay a month's interest if necessary to avoid selling any of my knives (only one month though, pay it off ASAP -- interest payments are wasted resources and should be avoided whenever possible). However, if you have to let one go, then your reasoning seems sound; just know that if you decide to replace it in the future, you'll probably pay a premium on the secondary market.