My son's LL has communal gear at all of the fields which include a Diamond mask, Pro Nine chest protector and Diamond shin guards as well as a plate brush and indicator. We provide a navy blue shirt and black cap as well for each of the team volunteer umpires so their out of pocket cost as a volunteer is zero other than time to learn.
In our district if you attend all 6 rules training nights, 1 four hour fast start umpire clinic (basic mechanics), the 8 hr mechanics course, the 1.5 hr advanced mechanics course and work 2 mentor games with a staff umpire then you qualify for certification,. With our league if you obtain certification and work 10 games for us we will reimburse the umpire up to $150 for the purchase of gear which means that most folks can get into officiating for little out of pocket and actually have a decent setup by the end of the season. Is this going to get them plate shoes, base shoes, several pants and full gear, no of course not but it is a good start for most of them.
The nice part of this is that there is little excuse for not helping out due to not having gear available and we typically replace the old gear after a season or two. Luckily a good chunk of the games get covered by folks who actually want to umpire and who have their own gear so our 'loaner' stuff is in really good condition typically when we finally retire it out and donate it to a Junior umpire for the next season.
This works for us but again we have a fairly good volunteer umpire core in our district.