HELP - the appraisal company gave me a super low-ball appraisal

[Elizabeth Rose]

Hi BP community! I would love some guidance here... 

I have been working with a credit union to get a HELOC to allow me to tap my equity to buy additional real estate. As a final step, they requested an in-person appraisal to confirm the value of my current residence. The appraiser ended up valuing my property at a good $50K LESS than I know it's worth given other comps in the area. I pushed back on this and requested a re-appraisal - I submitted comps showing what other less desirable condos in my area have recently sold for - but the appraiser is sticking to his estimate (of course he's not going to admit he made a mistake). The credit union has shrunk the loan amount they're willing to go with to match the appraisal. I've told them I'm unhappy with this and requested an appraisal by a NEW company, and even offered to pay for it... but they are saying no - I need to go with the current appraisal or they can't move forward.

I'd love any thoughts/feedback/ideas you may have on what to do here. I like this credit union (Bethpage) as they offer 85% LTV on condos while most other lenders only do 80%... but the final loan amount would be less than I could get from other lenders (even at 80% LTV) if these other lenders accept my condo for what I feel it's worth based on comps. The disadvantage here though is that I'd have to start the loan process all over again with a new lender...

Thanks in advance for your help!