Can anybody tell me what this is and if I should buy it?

[BigSiouxSaddlery]

This machine has had a number of modifications done.  Whether they are good or bad modifications is impossible to tell from a picture.  However, the Landis #1, although crude by today's standards, is a good machine if not worn out, and if set up correctly.  They are very simple and very forgiving.  I've paid as little as $50 and as much as $1000 for them.  If the machine sews, it's worth $500 all day long.  If there is a bobbin winder with it, consider it a $100-150 value.