I know Home Alone 3&4 are certainly not great but this is the cheapest I've seen all 4 films together. If you just want 1 & 2 they are only £3.97 at Tesco which also seems good.http://www.tescoentertainment.com/store/dvd/-/8:162536/
Features 'Home Alone' in which young Kevin McCallister has been mistakenly left at home in Chicago when his family rush off to spend Christmas in Paris. Initially he is delighted that he can eat and watch what he likes and go off to his bed any time he chooses. His newfound freedom is shortlived however, when his home becomes the target of two bungling burglars. Young Kevin must protect the house any way he can... 'Home Alone 2 - Lost In New York' in which once again Kevin McCallister is left to fend for himself when his folks accidentally leave him behind in New York. When the two burglars Harry and Marv show up Kevin spends the rest of the Christmas vacation making their lives hell... 'Home Alone 3' in which Alex has chicken pox and is home alone when an international team of criminals invade the area looking for a computer chip. The chip has accidentally found it's way into Alex's bedroom... and 'Home Alone 4' in which Kevin McAllister finds himself 'home alone' in the computer controlled house of his dad's new girlfriend, Natalie.