IEM suggestions (low budget)

220 compared to the sf.4. Well, it's been a while since i've owned the 220 but the sf.4 sound like a slightly better defined version of pretty much the same thing, there are several things that bother me about the sf.4 though, the supplied tips are either uncomfortable or the wrong shape, extension at both ends is pretty bad and microphonics are fairly poor. I got mine for £17 and for that I don't know of a better deal but I think £40 is seriously stretching their value. Have you found joker's review thread, it's the one comparing about 120 iem's and is one of the best threads on the site, it has in it pretty much all the high value budget earphones. Some are very good price in the UK, maybe look up; brainwavz m1, visang r02/r03, radiopaq ones etc. Those are not all earphone's i've owned but some often recommended one's in your price range. Most of them are through ebay though, if you want them quicker than about 2 weeks there'll be plenty more recommendations.

I haven't tried much in the low end IEM range, but I have tried the ViSang R03 and the Head-Direct RE2, and the R03s are an amazing value that I recommend to anyone and everyone. I don't know what the 220's sig is, but the R03 in a nutshell is:

Emphasis on the bass, a bit of a hump around 300 HZ
Decent mids IMO, the mids are very much the focus of these 'phones
Recessed treble, no sibilance, works well for low-quality recordings, passable detail nonetheless.
Not much in the way of "sparkle".
More full-sounding than a lot of the competition at its price point. Never sounds thin or tinny. Great at high volumes because of the sound signature (though I recommend EQing down the hump near 300 by about 4 dB or so) and never feels harsh, to summarize its sound I'd say 'smooth and full' or something to that effect.

Comfortable and shallow-fitting. Durable. Doesn't stick too far out of the ears-- I found I was able to lay my head on its side comfortably on a pillow with these in.
Easy to recable if necessary, you can just twist open the housing, though the cable seems very durable and probably will last a good while.

I have no idea what those 220s sounded like but I hope that info above helps to you figure out whether R03s are or are not something to look into.

The RE2s are decent (Nice airy treble, if a bit tinny sounding) as long as you don't mind fitting those massive biflanges into your ears. My ears can take a bit of a beating but those things are just too much for me.