Recording from the TV is not very practical on a DVD, you only get a couple of hours of decent quality so you end up hunting around for blank DVDs all the time, just like you would do with a VCR.
You also will not get a digital tuner at that price, just an analogue one, making the thing obsolete in a few years time.
To get a true upgrade from VHS and the feeling of "how I ever managed before" either go for a PVR, such as the Humax 9200 at £180.00 which gives you around 100 hours of recording onto a hard-drive and the ability to record 2 things at the same, or a DVD Recorder with a hard-drive that are typically around the £300.00 mark, but will not be as flexible as a PVR but will allow you to make your own DVDs.
If all you have is £100 to spend I would say it isn't worth spending in my opinion and you would be better off keeping the £100 in the bank. You are not going to anything decent for £100, yes you could get a cheap brand with analogue tuner, but decent?