So many of us are confused on how to do this achievement now I have a method to do it and will try again later on today, 5+K round 1 impossible? Not so much, as you know there is a time bomb you can get from the mystery box now this could be time consuming but slightly easier than other methods

Method; Get Time bomb from box, place time bomb down on round 1 (note you may have to restart game till you get bomb on round 1), now unlock the path to the haunted house also unlock the rooms where you are able to draw on chalk ie guns etc this is important! Dont forget to turn on power! and after all this has been opened finally open where you come out've the bank as there are 5 maybe 6 chalk drawings on the bored or you can keep going the long way, now obviously you will need to play a good few rounds to achieve this, now if your done the steps before go ahead and use your time bomb to take you back to round 1, all the paths will still be open and you haven't spent any money! Now go to the chalk room and pick up all the chalk an draw them around the map, notice that you will receive 1000 points for drawing each one, remember to turn power back on for pack a punch to work! now and this is complete you should have enough for pack a punch, now go to the haunted house and make it through to the maze, this is undoubtably the hardest step as the ghost will take money off you every time your hit by her! This happened to me and I went ape and haven't attempted it since haha, but if you make it through the house to the maze with 5k then just find your way to pack a punch and pack a punch your pistol, boom achievement! This could be easier in co-op with a friend to protect you from ghost

Hope this has helped and gets you the achievement