For adults, it really depends on how much you play. Regardless of this though you still 100% need to find boots that will feet your feet properly. You want to be able to flex your toes outwards, otherwise your foot will stay scrunched up inside of the boot for 2 hours. Imagine sitting uncomfortably for 2 hours… eventually you are going to get cramps. Similarly, if the blood flow is restricted … this will also lead to cramps. So, buy a boot that is wide enough for your foot.
If you play constantly and throughout the year then you should look at getting a top end boot. The build quality should be substantially better and will therefore last longer. Even if it doesn’t, football boots surprisingly have a warranty of about 2 years if the boot breaks for whatever reason. So if it breaks within 2 years provided you haven’t voided the warranty by oh I don’t know say playing on a surface that the boot was not intended for i.e. using firm ground boots on artificial grass surfaces. Then whoever you bought the boots off should replace them or at the very least give you a credit towards a replacement pair.
If you only play for half the year in a team that only trains once a week well then you could probably go for the low-end models. Realistically you will only be using them around 48 times with a maximum of 50 if your team makes finals. I use my boots everyday of every week so for me, comfort and quality is of the utmost importance otherwise I would be replacing them every 2 months.