You are in Bangkok wandering along the Khoa San Road and like many others before and you decide that a trip to the fabulous Angkor Wat - as featured in Lara Croft Tomb Raider - in Cambodia is a must.

The pictures in the travel agents windows that appear every few metres entice you, but not as much as the prices which promise to whisk you all the way to Siem Reap for only 300 baht (approx £4.40).

If this all sounds too good to be true, well unfortunately it is. All the travel agents have deals going with restaurants along the way and the guest houses, once you finally reach your destination.

In short these bus tickets are impossibly cheap for such a long journey and so there are various commissions that they try to extract from you throughout the journey.

The first part of the trip is easy enough, the roads are good and everyone is in high spirits. The buses normally leave around 7.30am from Bangkok and take about four hours to reach the Thai/Cambodian border at Poipet.

This is where the fun really starts. Rather than taking you right to the border they stop at their chosen restaurant anywhere from two to five kilometres away. It's time for lunch and of course a bit of a sales pitch.

Lunch is still cheap by our standards, but inflated by theirs, so that's commission number one gained. While you are eating, the driver and his colleague will come round with Cambodian Visa application forms, assuring you that they will take care of everything. Naturally, they say, getting the visa can be fraught with difficulties and huge queues, but that they can organise everything for you.

The going rate is about 1400 baht for this service, which means they gain a hefty 400 baht from you as the visa is only 1000 baht. If you accept their offer you have now more than doubled the cost of your trip and they have gained commission number two.

The other reason for this extended lunch time stop over is a delaying tactic, which will ultimately ensure commission number three.

Good to their word the visas are obtained, you make it safely over the border and on to your Cambodian bus. You settle back to watch the scenery and look forward to arriving in Siem Reap in about another four hours, leaving plenty of time to find a nice guest house and a restaurant for dinner, when you arrive.

Unfortunately the four hour journey stretches to seven hours or even as much as ten. When you finally arrive it's dark and you're tired and fed up, but luckily the bus has stopped at a great guest house they know. The owner comes out all smiles and the weary travellers give in and book rooms for the night.

Of course he's been expecting you all along and the inflated price you pay for your mediocre room ensures that your travel agent in Bangkok has gained commission number three.

So how do you get to Siem Reap without paying through the nose?

The way to do it is just to buy a ticket for the four hour journey to the border from Bangkok, this should cost you about 200 baht. When the bus stops for lunch and the sales pitch, you immediately gather your bags and flag down a Tuk Tuk (a three wheeled taxi), for the final few kilometres to the border. This shouldn't cost you more than about 50 to 60 Baht.

Once there, you refuse all offers of help from the visa touts, go straight through Thai immigration and then into to the official Cambodian Visa section. Make sure you have brought a passport sized photo with you otherwise you have to pay extra.

After filling out the application form you will usually receive your visa in about two minutes flat and at the normal government rate. Prices vary, but at the time it was several pounds cheaper to pay in dollars rather than Thai baht.

Once in Cambodia there are various options for getting where you want to go without the strings attached. The bus station is close by and your well deserved lunch will cost you a fraction of the price.

Happy travelling!