If only getting a visa was as easy as an attorney saying the case is strong. Why would someone pay for an attorney when they say the case is weak and needs more time together etc? You need to convince and show the consular that your relationship is legitimate and strong.
With regards on it being not cheap to come there, how much extra would it cost to get denied, have to not only have the petitioner visit again but also pay for another petition and wait another couple years?