The Golden Triangle is three cities and roughly 750 kilometres of road. Delhi to Agra is about 230 km on the Yamuna Expressway, Agra to Jaipur about 240 km, and Jaipur back to Delhi about 280 km. Those three drives are the whole shape of the trip, and the number of days you have decides how much of each city you actually see rather than pass through.
Below are 84 trips grouped by length, from two days to ten. Each one is run by a local operator and priced per person. Pick the length first, because that is the decision that matters, and the rest follows from it.
Two days covers Delhi and Agra properly, or Agra and Jaipur. It does not cover all three without spending the trip in a car, so most two-day trips drop one corner on purpose.

From $131 per person

From $146 per person

From $344 per person

From $281 per person

From $157 per person

From $245 per person

From $105 per person

From $192 per person

From $211 per person

From $53 per person

From $36 per person

From $94 per person

From $74 per person

From $140 per person
Three days is the shortest version of the full loop that works: a day in Delhi, the Taj at sunrise on day two, Jaipur on day three. Every drive is done in daylight.

From $328 per person

From $319 per person

From $178 per person

From $190 per person

From $695 per person

From $188 per person

From $132 per person

From $172 per person

From $319 per person

From $104 per person

From $193 per person

From $230 per person

From $215 per person
The fourth day is usually given to Jaipur, which needs it. Amber Fort, the City Palace and Jantar Mantar are a full day on their own without rushing any of them.

From $271 per person

From $230 per person

From $678 per person

From $1,459 per person

From $313 per person

From $1,563 per person

From $427 per person

From $395 per person

From $1,560 per person

From $900 per person

From $750 per person
Five days is the first length with slack in it. Fatehpur Sikri fits on the Agra to Jaipur leg, and a morning is free somewhere for whatever you liked most.

From $397 per person

From $637 per person

From $334 per person

From $261 per person

From $292 per person

From $282 per person

From $407 per person

From $280 per person

From $543 per person

From $303 per person

From $800 per person

From $310 per person
Six days usually adds a fourth stop. Ranthambore for tigers is the common one, and it has to be booked around the park rather than the other way round.

From $363 per person

From $2 per person

From $37 per person

From $323 per person

From $360 per person

From $407 per person

From $355 per person

From $407 per person

From $1,864 per person

From $923 per person

From $334 per person

From $438 per person

From $3,200 per person

From $405 per person
A week lets the triangle breathe and reach further, most often to Udaipur or Varanasi. The driving days stop being the shape of the trip.

From $438 per person

From $376 per person

From $923 per person

From $386 per person

From $448 per person

From $929 per person

From $479 per person

From $428 per person

From $501 per person

From $63 per person
Eight days and up are really a north India trip that happens to include the triangle, with the extra days going to Rajasthan or the Ganges.

From $1,069 per person

From $574 per person

From $719 per person

From $438 per person

From $480 per person
Ten days covers the triangle and a second region without a single rushed morning. This is the length people pick when it is their only trip to India.
If you are only taking one corner of the triangle, each city has its own day tours, guides and tickets.