Brrrr Appraisal uncertainty

[John Flanagan]

I am in the process of making an offer on a 2 family home. It is going for 300k cash quick close. It clearly needs 150k in work to get it up to rentable condition. I am unsure what it will appraise for because it is in a very desirable downtown area in a suburb that has very little inventory as of late. If there is inventory the homes are going for less because they are very old without any updates. My questions are:

1. How can I be sure that I will achieve an appraisal for the 450k that I put into it.

** Keep in mind multiple agents have told me that upon completion it can sell for 500k but I don't know what a bank will do without good comps.

2. Is there anything I can do during the renovation process to achieve a higher appraisal?

** I am also looking for the bets way to approach the appraiser so he or she realizes how much work was done on this home.

Thank you in advance for your thoughts.