I am trying to book travel to europe for may.

Most likely London. I am also considering going to Ireland or New Zealand or even Australia.

I am on a tight budget of 1500 bucks (including airfare hotel and a little spending money).

Should i be purchasing my ticket now, or waiting another month?

Are you planning on a long weekend? If not - your first step is to save up a lot more money - no way is $1500 going to cover air, hotels, food, sites etc for a trip to any of these places for more than 4 or 5 days - even at the superbudget level.

Where are you flying from? With $1500 I can't see how you could spend more than a couple of days in London or Ireland, or even get to New Zealand of Australia - unless you're in Hawaii or something..........

If you are flying from the East coast to Europe, you can easily get by with $1500 if you do your homework and are flexible with flight times.

For a week: figure $500 for airfare(maybe less), $500 for lodging(much less if you use hostels), $300 for transportation(less if you stay in one area), and $200 for cheap eats and sights. Ultimately doable. Check out Rick Steves Europe throught the back door.

PS If you know where you want to go, and the ticket is less than $500, book it now.

American Airlines has Boston to London flights for $550ish - a pretty good price for May.

Go for it.

Check out the low price hotel options others have suggested, use the tube/bus, eat cheaply and enjoy!

Gayle

Staying in hostels saves money for sure, but if you want an individual room, student accommodation can also be very cheap:
http://www.venuemasters.co.uk/holiday_travelstay.asp