I've had extensions for 3 years, about to have another set put in end of the month.
First time I had a weave plus nanos
Second time just a weave but went extreme with 30inches, 240 grams in total!
This next time I'm debating between the same again or a secret weave but shorter.
My hair has grown so much since having them, but I was bored of my bob and longed for long hair as opposed to having hair that breaks.
I personally struggled with a proper blow dry, and it is important to really dry the roots so I have a weekly blow dry and the hairdressers and refit and colour every 8-9 weeks. My last set has lasted 18 months.
I also sleep with a satin hat to keep them in good condition.
I'd say as well as the cost implications, you also need to think about lifestyle, my hairdresser has had people who swim lots, pools, holidays etc and they are lucky to get 8 months out of a set before they need replacing - for a set, colour and fitting I'm looking around £1k. For me, that's a lot of money so I want to look after them as long as possible.
The other aspect is the hairdresser will need to thin your hair on the ends to blend, it's not an issue for fitting, but if you choose to remove you'll likely need an inch or two off your length so your hair doesn't look straggly and thin.
If you're in Lincolnshire I can recommend my salon, but best thing is ask around, have a consultation or two and see who you feel comfortable with