Verina, you can easily make mistakes in the Budapest property market. All you need to do is read through the posts on this forum. In many cases, the wrong type or overpriced classic properties were bought during the boom years of 2002-2004. More recently, buyers of new-builds have frequently had to deal with low build quality, rental problems, overpricing and endless snag lists.
Most analysts would suggest that for the longer time frame - i.e. longer than 8 years, that good quality classic properties in premier locations make the most investment sense. Standard new builds for the most part are too expensive, poorly located and don't hold their quality over a long-term period. Take a look at some developments from 3-4 years ago. Many of them look like they need renovation already. My opinion is that the right classic property in the right location can only improve in quality, e.g. when the building is renovated, the block is renovated, street pedestrianised, etc. However, the 'right' classic property is extremely difficult to find as the market is clogged with the 'wrong' type - overpriced, dark, poor condition of building/block, secondary location, noise problem, poor aspect or position in building, etc..
To answer your question, Warsaw is much more expensive then Budapest at the minute because the Polish economy is doing well and Poles can afford to purchase at the minute, while austerity measures in Hungary mean that locals are not buying here at the minute. They're holding out, seemingly until after 2009, when these measures are relaxed and when the economy will hopefully get back on its feet. Many anomalies exist in Budapest, when compared with Warsaw. Bp has higher incomes, wealthier people, one of the best supplies of neo-classical property in the world and a much higher attraction for a foreigner coming to live here, much better foreign-rental market, higher FDI per person, etc. but at the minute, Warsaw is leading the way in terms of number of purchases and capital appreciation.
I will PM you a contact for an excellent bilingual lawyer, who I've used many times before.
In general, locals in Bp prefer new-builds, because finance is a lot easier to obtain, with up to 100% mortgages available. A cash-strapped buyer will take what he can afford. Other benefits are secure parking, 'Western'-style layout/atmosphere and clean common areas (not very common in Budapest!). My preference and that for the majority of others who can afford lower LTV rations is for a perfect classic apartment in an excellent location, in either a beautiful classic building (renovated or with a concrete plan for renovation). By purchasing these type of properties, I can have the best of both worlds, but most importantly, own an apartment that should become more and not less desirable in the long-term.
In terms of supply and demand, there is an absolute over-supply of new builds in almost every secondary location in the city, while there is a total lack of reasonably-priced, unproblematic classic properties in premier locations. The latter sell extremely quickly.