because I was able to save up for my favourite model of guitar. I still don't think the cheap one was a bad guitar. it's a completely different style. most beginners guitars are modelled on a Statocaster type design and scale length. my expensive guitar is a Gibson SG. the neck is much shallower, and the fret scale is shorter. so as a short person with smallish hands, it's easier for me to play. the pickups are a different style, and give a different, crunchier sound more suited to the sort of music I like playing. the cheap one has a whammy bar, which my expensive one doesn't, so for songs where that is useful, that's the one I'll use, and generally sounds much smoother unless I use distortion pedals. they're very different guitars. but the price of the cheaper one doesn't make it a bad guitar. it's perfectly decent.
they sound and play differently. this doesn't mean the cheap one isn't good, it means that I use them for different things. the one I literally saved up for for a few pounds here, a few there, for over a year, obviously, means more to me emotionally. but also, the other was my first guitar that I learned on, and I still love it. they both have their strengths and weaknesses.
I've never felt a need to buy an ACTUAL stratocaster to replace my stratocaster based beginners kit guitar, because I've got that style and sound covered already. I quite fancy a Jaguar or Telecaster style one at some point, but it wouldn't have to be the Fender originals. I'd settle for a Squier one (their budget range) or even just a knockoff type. saw a lovely powder blue telecaster style economy guitar last week that could tempt me. it was cute as hell, and not very expensive at all.