There are 52 weeks in a year.
For the first year, Thomas received 52 x 50 = $<<52*50=2600>>2600
In the second year, Thomas earned 9 x 30 = $<<9*30=270>>270 a week
In a year, Thomas earned 52 x 270 = $<<52*270=14040>>14,040
The total for the two years is 14040+2600 = <<14040+2600=16640>>16640
In 2 years, Thomas' weekly expenses amounted to $35 x (52 x 2) = $35 x 104 = $<<35*52*2=3640>>3640
By the end of 2 years, Thomas would have saved $16640 - $3640= <<16640-3640=13000>>13000
Thomas still needs $15,000 - 13000 = $<<15000-13000=2000>>2000
#### 2000