just bought a caulking gun (yeah, you know, those gun thingies for oushing t he innards out of sealant tube) for £ 1 at Poundland; be interested to see how long it lasts

Should be okay as long as you're not doing visable stuff.... The cheaper ones jam and judder and make it difficult to get a good bead. My cheapo one was in the garage and I ended up getting ripped off at Travis Perkins for a good'un. Makes neat beads so much easier though....

Don't use it, put it in a vacumn sealed case and it will last forever.