20 units multifamily owner can't show proof of income via bank statements

[Jeremy Altdorfer]

So there is a 20 unit building I'm attempting to buy, I made an offer of 1,500,000, 60 days inspection period and cash close, need to see 3 years of bank statements as proof of income. Owner came back at 1,550,000 with 30 days inspection. Sure that's fine but.... the owner said he used multiple bank accounts to collect rents and thus can't provide the 3 years statements since they bought 2022 so not 3 years. How else can I verify past performance? I would assume asking proof of income on something like this is not unusual to request in a sale. I also know they had one deal fall through after 4 months under contract and they want to sell because they are having trouble managing remotely. My only backup plan if I can't get verified funds is to assume the worst and to drop my counter offer even lower than my original due to the risk I would be taking on, and then when I do my in person inspection try and guess what rents are fair market for the empty units, and ask as many tenants as I can what they pay in rents monthly.