Need advice: Very small sample

I'm looking for advice. I'm trying to predict the question mark using the following tiny data set.

Tag1 Tag2 Tag3 Tag4 Score 1 0 0 0 2000 1 0 0 1 2400 0 1 0 0 3000 0 1 0 1 3600 0 0 1 0 4000 0 0 1 1 ? 

I'm expecting the answer to be 4800. I'm very new to this space. I've tried a quick linear regression algorithm but the results aren't great. I've tried a simple neural network but I appreciate that I don't have enough samples to allow this approach to work.

I feel like my options now are to either find another approach or invest the time in understanding how to apply one of the two approaches that I have tried so properly. Any advice at all would be appreciated.