hows this for a 60 percent pa return

my brother had an ordinary old 16" caravan that had been sitting around not being used....took it to qld for holidays,,,,did not want to tow it back south...so he rented it out 60.00 pw the tenants pay the park fees about 80 pw...the van cost 5000...returns 3120 pa.....permanent park residents...not just seasonal
wondering if I should buy a couple of vans and do the same..
say 5 vans @ 5000 = 25,000 capital costs
rent 5 @ 60 = 300pw or 15600 pa...its a lot different to buying one house for a similar weekly rental
no capital gains but might be an idea for those wanting some pocket money