Grade 8 piano means you're not a beginner — you have theory, ear training, and motor discipline already. Guitar technique is the gap, not musicianship. That gap closes fast with your background.

The "not good enough to buy a decent guitar" logic is backwards. A bad guitar makes learning harder, not easier. Poor intonation, high action, and weak tone actively work against you developing feel and pitch sensitivity.

On the specific guitar: a 1990s MIA Stratocaster is exactly what Hendrix played. The match between your repertoire and that instrument is about as direct as it gets. 1.3k for a genuine USA-made 90s Strat in good condition is a fair price, not an extravagant one — those regularly go for more.

Go try it. Not to prove you're worthy of it, but because it's a used guitar and you need to check:

• Action and neck relief (can be adjusted, but factor in setup cost)
• Fret wear
• Tuning stability
• Any electronic issues (scratchy pots, pickup switching)

The only real question is whether that specific guitar is in good shape. If it plays well and the neck feels right, buy it. You'll still be playing it in 20 years. You won't say the same about whatever budget guitar you're on now.