US$ 3 Billion.....with that dough you can buy the complete DR (with a coupon)
The SD Metro is already at about US$2.4 billion without taking into account the actual amount of each line in today's dollars starting with the first one, operational costs of every year, the costs of the added train cars, maintenance costs of every year, the cable cars lines cost, the monorail and cable cars line in Santiago costs, and the cost of the current extension of the 2nd line of SD Metro which is over budget and growing.
That is just the SD Metro, ST Monorail, SD Cable Cars Lines and the ST Cable Cars Line. The government spends a lot of money every year on other things too from road construction/maintenance to creating new hospitals and remodeling the old ones, nothing of the police is free, CESFRONT cost quite a dime too, etc.
The Dominican government has a yearly budget that surpasses US$8 billion. That is just the government, but in reality there is the private sector too (formal and informal.) The DR as you see it consumes a pretty penny from everybody year in, year out. Despite that, it's still not enough due to its developing situation. If it was a developed country it woukd consume more!