IV Have This Penny Black For A While.

Just wondering if this is rare or worth anything thanks

Not rare, but in higher than average demand

Assuming it is real the stamp clearly has two points strongly in its' favour: It has four clear margins and a recognizable maltese cross cancel that has not obliterated the stamp. It looks like a desirable specimen of a very desirable stamp.

There's at least two strikes of the Maltese Cross cancellation.

The stamp is a plate 4 by the looks.

Catalogue value in the QV Vol. 1 Part 1 is £400

A scan would help identifying the plate it was printed from. I agree with Bobby De La Rue it looks like a plat 4 example.

Penny Blacks are very common stamps. Condition is very important. Your stamp looks clean, has not been obliterated and even has crisp strikes of the red Maltese Cross, it has four good (top right) to very large margins. In all that looks like a stamp of the quality the Stanley Gibbons catalogue prices, if not better.

Even such stamps are not very rare, but demand for them is high. It should have no problem selling for GBP 100 or a bit more (if it is in as good condition as it appears).