If you don't have decent gear - pedals/cleats/shoes, shorts, jerseys, sunglasses (eye protection), jacket, gilet, helmet, gloves, etc. - I'd buy low on the bike and think about all the "little things" that will add up to complete the budget.

Then after you've done a few thousand kms, you'll have a much better idea of exactly what you want in a bike, and you can transfer all of those goodies with you to the new bike.