Drag Rear Tyre Advice
I've run bias ply slicks with small radial fronts several times without a issue. The mph range was 105 or less, so that may have helped? Plus I had 45+ lbs in them for track use, so I don't know if they even realized they were radials...:D
I would match them if possible, but for a few times out here and there, I doubt it will be a issue.
With that said, while I believe it's more of a "street" issue, your safety is of utmost importance, so if anyone has had a handling or braking issue at the track, I hope they post here...
As far as the "cheap" Mickey's, I supposed you're looking at a used set? Just make sure they have enough life in them to warrant what you're going to pay.