Two deals that stand out for your requirements are as follows
At the top of your budget is the
Special edition all the bells and whistles two hard drives 1 solid state one 7200 rpm additional storge, core i7, 16 gigs ram upgradable to 64 gigs with Windows Home 10.
Top of budget you can add 23 inch monitor option
More Budget friendly XPS Standard Desktop
XPS 7200 rpm 1 TB , core i7, 8 gigs ram upgradable to 64 gigs with Windows Pro 10 This is below budget and a good buy you can add optional 24 inch monitor