Please tell us all which club you play for and how you raise between £5k-£10k through a sponsored agreement with anyone via cricket as I would be keen as mustard to understand that.
replying to everyone generally: when I was treasurer of a medium sized club we used to get about £1500 from advertising boards, £1000 in shirt and website sponsorship (mostly from local pubs), £1000 from bonus ball club, £1000 from a race night, and maybe £1000 in total from other fundraising events (eg a quiz night, 6 aside tournament).
So you can easily get £5000 without having to ask players to dip their hands in their pockets. That's enough to cover groundsman (about £2500) insurance, match balls, topping up the kit bag, and have some left over to save for emergencies.
If you want any more advice just ask. I was treasurer for 5 years.