@Jerry Hollifield is correct. It all boils down to the definitions of "residential" and "commercial" which lenders have defined for us investors. That being said, there are always exceptions. I have colleagues with close relationships to lenders that were able to treat a 4-plex as a "commercial" property. Properties 1-4 units are deemed "residential" and are valued based on comparables. Properties with 5+ units are deemed "commercial" and values are based on NOI. Why? No clue and really don't care. I'm sure a savvy BP member knows the justification behind this distinction.
Understanding those definitions, the ARV of your 4-plex would be valued based on comps in your market (other 4-unit properties in your market) since it is treated as residential property. Best advice I can give is present your business plan to 2-3 lenders and get their feedback on ARV. Depending on your strategy with this property it could still be a good deal. All in for $240K. Lets assume best case scenario rents bump to $3000/month, that's a $900/month increase or $10,800/year increase giving you a 25% ROI on your reno costs. You're above the 1% rule, get to take advantage of bonus depreciation (I recommend conducting a cost seg analysis), and you're positive cash flow. If you wanted to flip it sell the story - turnkey 4-plex, recently renovated cash flowing X amount per month.
Hope this answers your questions and gives you some exit strategies. BTW... if you find more 4 unit properties like this let me know! Where are you located?